List of top Chemistry Questions

Give chemical tests to distinguish between the following pairs of compounds:
(i) Phenol and Benzoic acid:
(ii) Propanal and Propanone:

What is meant by a unidentate ligand? Give an example.

Write the IUPAC name of the given compound:

Which one of the given compounds is a stronger acid and why?
CH$_2$FCH$_2$COOH or CH$_3$CHFCH$_2$COOH

What happens when glucose reacts with bromine water? Write the chemical equation.

Which compound in the given pair will undergo S$_N$2 reaction at a faster rate and why?
CH$_3$–CH$_2$–I and CH$_3$–CH$_2$–Br

Write the electronic configuration for d$^4$ ion if \( \Delta_0 < P \) on the basis of crystal field theory.

Arrange the following compounds in the increasing order of their boiling points:
Butane, 1-Bromobutane, 1-Iodobutane, 1-Chlorobutane

How will you convert the following?
(i) Toluene to Benzoic acid:
(ii) Ethanol to 3-Hydroxybutanal:

18 g of a non-volatile solute is dissolved in 200 g of H$_2$O, and it freezes at 272.07 K. Calculate the molecular mass of the solute (K$_f$ for water = 1.86 K kg mol$^{-1}$).

Assertion (A): Fructose is a reducing sugar.
Reason (R): Fructose does not reduce Fehling solution and Tollen’s reagent.

Assertion (A): p-nitrophenol is less acidic than phenol.
Reason (R): Nitro group is electron-withdrawing and helps in the stabilization of p-nitrophenoxide ion.

Define the following terms:
(a) Order of Reaction:
(b) Activation Energy:

Assertion (A): Benzoic acid does not undergo Friedel – Crafts reaction.
Reason (R): Carboxyl group is deactivating and the catalyst aluminium chloride gets bonded to the carboxyl group.

Assertion (A): For a Daniell cell, Zn/Zn$^{2+}$(1M) || Cu$^{2+}$(1M)/Cu with \( E_{\text{cell}} = 1.1 \, V \), if the external opposing potential is more than 1.1 V, the electrons flow from Cu to Zn.
Reason (R): Cell acts like a galvanic cell.

Match the reagents required for the given reactions: I. Oxidation of primary alcohols to aldehydes (p) \(NaBH_4\)
II. Butan-2-one to Butan-2-ol (q) 85% phosphoric acid at 440 K
III. Bromination of Phenol to 2, 4, 6- (r) PCC Tribromophenol
IV. Dehydration of propan-2-ol to (s) Bromine water propene

The Valence Bond Theory (VBT) explains the formation, magnetic behaviour and geometrical shapes of coordination compounds whereas ’The Crystal Field Theory’ for coordination compounds is based on the effect of different crystal fields (provided by ligands taken as point charges), on the degeneracy of d-orbital energies of the central metal atom/ion. The splitting of the d-orbitals provides different electronic arrangements in strong and weak crystal fields. The crystal field theory attributes the colour of the coordination compounds to d-d transition of the electron. Coordination compounds find extensive applications in metallurgical processes, analytical and medicinal chemistry.
Answer the following questions:

Write the structures of A and B in the following reaction: \[ \text{C}_6\text{H}_5\text{COOH} \xrightarrow{\text{NH}_3, \Delta} A \xrightarrow{\text{Br}_2/\text{NaOH}} B \]

Write a simple chemical test to distinguish between methylamine and aniline.

Write the chemical reaction involved in Gabriel phthalimide synthesis.

How will you convert aniline to p-bromoaniline?

Complete the following reaction: \[ \text{C}_6\text{H}_5\text{N}_2^+Cl^- \xrightarrow{\text{(i) HBF}_4} \xrightarrow{\text{(ii) NaNO}_2/\text{Cu}, \Delta} \quad ? \]

Why are equimolar solutions of sodium chloride and glucose not isotonic?

Out of chlorobenzene and 2,4,6-trinitrochlorobenzene, which is more reactive towards nucleophilic substitution and why?